RMS Trimode: please add TRX control via PTC-2

Especially for sysops who use Bluetooth connection to the modem (better RF isolation) the CAT control of the transceiver direct via PTC or Dragon is needed. It should not be a major problem to add this - the TRX CAT can be accessed via a dedicated hostmode channel. The commandset is the same as via a second comport. (transfer command)